DFSMShsm Fast Replication Technical Guide

Front cover DFSMShsm Fast Replication Technical Guide Keith Winnard Jeanne Vangsness In partnership with Academy of Technology Redbooks

International Technical Support Organization DFSMShsm Fast Replication Technical Guide April 2015 SG24-7069-02

Note: Before using this information and the product it supports, read the information in Notices on page ix. Second Edition (April 2015) This edition applies to z/os Version 2, Release 1 of Data Facility Storage Management Subsystem (DFSMS) (product number 5650-ZOS). Copyright International Business Machines Corporation 2015. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.

Contents Notices................................................................. ix Trademarks...............................................................x IBM Redbooks promotions................................................. xi Preface................................................................ xiii Authors................................................................. xiii Now you can become a published author, too!.................................. xiv Comments welcome........................................................xv Stay connected to IBM Redbooks.............................................xv Chapter 1. DFSMShsm fast replication overview............................... 1 1.1 DFSMShsm fast replication sample configuration.............................. 2 1.1.1 Fast replication diagram............................................. 2 1.1.2 FlashCopy function overview......................................... 2 1.2 Fast replication review.................................................. 3 1.2.1 Point-in-time hardware support........................................ 3 1.2.2 FlashCopy: Background copy......................................... 4 1.2.3 FlashCopy: No background copy...................................... 5 1.2.4 FlashCopy Version 1................................................ 6 1.2.5 FlashCopy Version 2................................................ 6 1.3 DFSMShsm FRBACKUP new features...................................... 7 Chapter 2. Planning for FRBACKUP......................................... 9 2.1 General FRBACKUP usage and planning considerations...................... 10 2.1.1 DFSMShsm FRBACKUP system overview.............................. 10 2.1.2 FRBACKUP intended use........................................... 11 2.2 FlashCopy considerations that relate to FRBACKUP.......................... 12 2.2.1 FlashCopy target volume types....................................... 12 2.2.2 FlashCopy stages................................................. 12 2.3 FlashCopy options.................................................... 12 2.3.1 Full volume FlashCopy............................................. 13 2.3.2 FlashCopy with no background copy (NOCOPY)......................... 14 2.3.3 FlashCopy with background copy..................................... 14 2.3.4 FlashCopy NOCOPY to Space Efficient target volume..................... 14 2.3.5 Incremental FlashCopy............................................. 16 2.3.6 FlashCopy consistency groups....................................... 18 2.4 Remote Pair FlashCopy................................................ 18 2.5 FRBACKUP planning considerations for DB2................................ 20 2.5.1 Planning for the DB2 application data pool.............................. 20 2.5.2 Planning for the DB2 log volumes data pool............................. 22 2.5.3 FRBACKUP target configuration for a DB2 subsystem.................... 24 2.5.4 System overview of FRRECOV from DB2 data CPBSG.................... 25 Chapter 3. Storage management subsystem environment...................... 27 3.1 SMS constructs....................................................... 28 3.2 SMS constructs for fast replication........................................ 29 3.2.1 Copy pool....................................................... 29 3.2.2 Copy pool backup storage group..................................... 30 Copyright IBM Corp. 2015. All rights reserved. iii

3.3 ISMF panels......................................................... 31 3.4 Preparing for DFSMShsm fast replication................................... 32 3.4.1 Defining copy pools................................................ 32 3.4.2 Defining copy pool backup storage groups.............................. 36 3.5 Considerations....................................................... 39 3.5.1 DB2............................................................ 39 3.5.2 SMS constructs that span storage controllers............................ 40 3.5.3 Extend and overflow storage group types............................... 41 3.5.4 GRSplex........................................................ 42 3.5.5 Sysplex with multiple DFSMS levels................................... 42 3.6 NaviQuest changes for DFSMShsm fast replication........................... 43 3.7 Lab environment for our tests............................................ 44 Chapter 4. DFSMSdss interface considerations.............................. 49 4.1 DFSMSdss functions that are used by DFSMShsm........................... 50 4.1.1 DFSMSdss full copy with DUMPCONDITIONING........................ 52 4.1.2 Other DFSMSdss COPY parameters.................................. 54 4.1.3 Remote Pair FlashCopy (RPFC)...................................... 55 4.1.4 Count key data volume FlashCopy support............................. 56 4.1.5 DFSMSdss COPY options that are invoked by DFSMShsm................ 57 4.1.6 FRBACKUP invokes DFSMSdss for full volume copy..................... 58 4.1.7 Full DUMP from FRBACKUP target volumes............................ 58 4.1.8 FRRECOV invokes DFSMSdss...................................... 60 4.2 Application interfaces.................................................. 64 4.2.1 ADREID0 mapping macro........................................... 64 4.2.2 ADRUFO mapping macro........................................... 64 4.2.3 ADRUIXIT installation exit........................................... 64 Chapter 5. DFSMShsm fast replication commands............................ 65 5.1 FRBACKUP techniques................................................ 66 5.1.1 Non-incremental DASD backup...................................... 66 5.1.2 Incremental DASD backup.......................................... 66 5.1.3 DASD backup without background copy................................ 67 5.1.4 Metro Mirror and FlashCopy......................................... 68 5.1.5 FlashCopy consistency groups....................................... 68 5.2 DFSMShsm fast replication commands.................................... 68 5.2.1 FRBACKUP command............................................. 70 5.2.2 FRRECOV command.............................................. 71 5.2.3 FRDELETE command.............................................. 71 5.2.4 SETSYS for specifying fast replication methods.......................... 71 5.3 Examples of DFSMShsm fast replication tasks............................... 72 5.3.1 Verification of a copy pool environment................................ 72 5.3.2 Volume preferencing............................................... 74 5.3.3 Copy pool backup with background copy............................... 76 5.3.4 DASD fast replication backup without background copy.................... 82 5.3.5 Dumping a fast replication backup to tape.............................. 85 5.3.6 Recovery from fast replication backups............................... 101 5.3.7 Changing the number of backup copies setting on copy pools.............. 138 5.4 Correcting mismatched preassigned volume pairs........................... 146 5.4.1 FRDELETE command............................................. 146 5.4.2 LIST command.................................................. 146 5.4.3 Deleting preassigned pairs......................................... 147 Chapter 6. DFSMShsm fast replication security............................. 149 iv DFSMShsm Fast Replication Technical Guide

6.1 Security for DFSMShsm fast replication................................... 150 6.2 The RACF FACILITY class............................................. 150 6.2.1 RACF considerations............................................. 151 6.2.2 User access.................................................... 152 6.2.3 DFSMShsm QUERY SECURITY command............................ 153 6.3 Identifying the DFSMShsm started task to RACF............................ 154 6.3.1 Configuring DFSMShsm to invoke DFSMSdss as a started task............ 154 6.3.2 DFSMSdss address spaces started by DFSMShsm...................... 154 Chapter 7. Using DFSMSdss to back up copy pools.......................... 157 7.1 The requirement to back up copy pools................................... 158 7.2 Dump and restore procedures by using DFSMSdss.......................... 158 7.2.1 DFSMSdss DUMP procedure....................................... 159 7.2.2 DFSMSdss RESTORE procedure................................... 160 7.3 Restoring the DFSMSdss dump......................................... 160 7.3.1 Restoring to the FRBACKUP source volume........................... 161 7.3.2 Restoring to volumes in another system............................... 162 Chapter 8. Using DFSMShsm fast replication............................... 165 8.1 DB2 uses DFSMShsm fast replication.................................... 166 8.1.1 Backup and recovery solution....................................... 166 8.1.2 DFSMShsm commands to support fast replication....................... 166 8.2 DB2 uses FlashCopy through DFSMShsm................................. 167 8.2.1 Preparing for DFSMShsm fast replication.............................. 169 8.2.2 Serialization.................................................... 170 8.2.3 Copy pool construct for DB2........................................ 170 8.2.4 Copy pool backup storage group.................................... 170 8.3 DB2 backup by using DFSMShsm fast replication........................... 171 8.3.1 DB2 BACKUP SYSTEM utility...................................... 171 8.3.2 DB2 BACKUP SYSTEM processing.................................. 172 8.4 Use of DB2 tokens................................................... 173 8.5 BACKUP SYSTEM................................................... 174 8.6 BACKUP SYSTEM to DASD............................................ 178 8.7 BACKUP SYSTEM to tape............................................. 180 8.7.1 DUMP......................................................... 180 8.7.2 DUMPONLY.................................................... 180 8.8 BACKUP SYSTEM additional considerations............................... 181 8.8.1 DATA ONLY.................................................... 181 8.8.2 FORCE........................................................ 182 8.8.3 TOKEN........................................................ 182 8.8.4 FlashCopy consistency group support................................ 183 Chapter 9. Using DFSMShsm fast replication in an environment outside of DB2.. 185 9.1 Environments outside of DB2........................................... 186 9.1.1 Candidates..................................................... 186 9.1.2 Planning a copy pool.............................................. 186 9.1.3 Prevent DFSMShsm functions from processing target volumes............. 187 9.1.4 Serialization.................................................... 187 9.1.5 Preparing copy pools for fast replication............................... 187 9.1.6 Obtaining DFSMShsm fast replication backup information................. 187 9.1.7 Recovering..................................................... 189 9.1.8 Withdrawing DFSMShsm background copies........................... 191 9.1.9 Deleting unneeded fast replication backup versions...................... 191 9.1.10 Recovery after increasing the number of volumes in a copy pool........... 192 Contents v

9.1.11 Recovery after decreasing the volumes in a copy pool.................. 192 9.1.12 Decreasing volumes in a copy pool backup storage group................ 193 9.1.13 Catalogs...................................................... 193 9.2 zfs aggregate environments........................................... 193 9.2.1 zfs aggregate backup example..................................... 194 9.2.2 zfs aggregate recover example..................................... 196 Chapter 10. Reporting on the DFSMShsm fast replication environment.......... 201 10.1 Statistics records.................................................... 202 10.2 REPORT command................................................. 202 10.2.1 REPORT DAILY command........................................ 202 10.2.2 REPORT VOLUMES command.................................... 202 10.2.3 REPORT statistics.............................................. 203 10.3 Updated DSR records................................................ 204 10.4 Updated VSR records................................................ 204 10.5 New FSR records................................................... 204 10.5.1 FSR type 21................................................... 204 10.5.2 FSR type 22................................................... 204 10.5.3 FSR type 23................................................... 205 10.5.4 Gathering the data.............................................. 207 10.5.5 Preparing for analysis............................................ 208 10.5.6 Report Generator............................................... 209 10.5.7 Sample REXX execs............................................. 221 10.5.8 Creating reports................................................ 222 10.5.9 Customizing reports............................................. 223 10.6 Other report sources................................................. 224 10.6.1 Log data sets.................................................. 224 10.6.2 Problem Determination Aid trace................................... 224 10.7 Messages with DFSMShsm fast replication............................... 225 10.7.1 Updated messages.............................................. 225 10.7.2 New messages................................................. 226 Chapter 11. Error recovery and debugging................................. 227 11.1 Messages with DFSMShsm fast replication............................... 228 11.1.1 DFSMShsm fast replication volume error messages.................... 228 11.1.2 Message routing................................................ 229 11.1.3 Messages with DB2............................................. 230 11.2 Patches for performance measurements................................. 231 11.2.1 Overview...................................................... 231 11.2.2 Patching to turn off performance and additional messages............... 232 11.3 Debugging FRBACKUP errors......................................... 232 11.3.1 DFSMShsm Problem Determination Aid (PDA) tool..................... 232 11.3.2 Preparing for problems with source to target volume pairing.............. 232 11.3.3 FORCE situations............................................... 233 11.3.4 Capturing catalog information errors................................. 234 11.4 FRDELETE considerations............................................ 234 11.5 Decreasing copy pool backup volumes................................... 235 11.6 Reuse of invalid backup versions....................................... 235 11.7 AUDIT COPYPOOLCONTROLS....................................... 236 11.7.1 Fast replication and associated control data set records................. 237 11.7.2 G is the dump generation record (DGN).............................. 241 11.7.3 Y is the dump volume record (DVL)................................. 241 11.8 Messages with DFSMShsm fast replication............................... 242 vi DFSMShsm Fast Replication Technical Guide

Appendix A. Sample REXX execs......................................... 243 Sample REXX RXZFS.................................................... 244 Sample REXX RXSUSH.................................................. 248 Sample CONVTOD to convert the TOD....................................... 254 Related publications.................................................... 257 IBM Redbooks.......................................................... 257 Other publications....................................................... 257 Online resources........................................................ 258 Help from IBM.......................................................... 258 Index................................................................. 259 Contents vii

viii DFSMShsm Fast Replication Technical Guide

Notices This information was developed for products and services offered in the U.S.A. IBM may not offer the products, services, or features discussed in this document in other countries. Consult your local IBM representative for information on the products and services currently available in your area. Any reference to an IBM product, program, or service is not intended to state or imply that only that IBM product, program, or service may be used. Any functionally equivalent product, program, or service that does not infringe any IBM intellectual property right may be used instead. However, it is the user's responsibility to evaluate and verify the operation of any non-ibm product, program, or service. IBM may have patents or pending patent applications covering subject matter described in this document. The furnishing of this document does not grant you any license to these patents. You can send license inquiries, in writing, to: IBM Director of Licensing, IBM Corporation, North Castle Drive, Armonk, NY 10504-1785 U.S.A. The following paragraph does not apply to the United Kingdom or any other country where such provisions are inconsistent with local law: INTERNATIONAL BUSINESS MACHINES CORPORATION PROVIDES THIS PUBLICATION "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Some states do not allow disclaimer of express or implied warranties in certain transactions, therefore, this statement may not apply to you. This information could include technical inaccuracies or typographical errors. Changes are periodically made to the information herein; these changes will be incorporated in new editions of the publication. IBM may make improvements and/or changes in the product(s) and/or the program(s) described in this publication at any time without notice. Any references in this information to non-ibm websites are provided for convenience only and do not in any manner serve as an endorsement of those websites. The materials at those websites are not part of the materials for this IBM product and use of those websites is at your own risk. IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring any obligation to you. Any performance data contained herein was determined in a controlled environment. Therefore, the results obtained in other operating environments may vary significantly. Some measurements may have been made on development-level systems and there is no guarantee that these measurements will be the same on generally available systems. Furthermore, some measurements may have been estimated through extrapolation. Actual results may vary. Users of this document should verify the applicable data for their specific environment. Information concerning non-ibm products was obtained from the suppliers of those products, their published announcements or other publicly available sources. IBM has not tested those products and cannot confirm the accuracy of performance, compatibility or any other claims related to non-ibm products. Questions on the capabilities of non-ibm products should be addressed to the suppliers of those products. This information contains examples of data and reports used in daily business operations. To illustrate them as completely as possible, the examples include the names of individuals, companies, brands, and products. All of these names are fictitious and any similarity to the names and addresses used by an actual business enterprise is entirely coincidental. COPYRIGHT LICENSE: This information contains sample application programs in source language, which illustrate programming techniques on various operating platforms. You may copy, modify, and distribute these sample programs in any form without payment to IBM, for the purposes of developing, using, marketing or distributing application programs conforming to the application programming interface for the operating platform for which the sample programs are written. These examples have not been thoroughly tested under all conditions. IBM, therefore, cannot guarantee or imply reliability, serviceability, or function of these programs. Copyright IBM Corp. 2015. All rights reserved. ix

Trademarks IBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both. These and other IBM trademarked terms are marked on their first occurrence in this information with the appropriate symbol ( or ), indicating US registered or common law trademarks owned by IBM at the time this information was published. Such trademarks may also be registered or common law trademarks in other countries. A current list of IBM trademarks is available on the Web at http://www.ibm.com/legal/copytrade.shtml The following terms are trademarks of the International Business Machines Corporation in the United States, other countries, or both: DB2 DS8000 FICON FlashCopy GDPS HyperSwap IBM MVS RACF Redbooks Redbooks (logo) System Storage z/os The following terms are trademarks of other companies: Linux is a trademark of Linus Torvalds in the United States, other countries, or both. SAP is a registered trademark of SAP SE in Germany and in several other countries. Other company, product, or service names may be trademarks or service marks of others. x DFSMShsm Fast Replication Technical Guide

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Preface DFSMShsm fast replication provides DFSMShsm management for the use of volume-level fast replication. Fast replication is made possible by using the FlashCopy capability of storage servers. With this capability, a set of storage groups can be defined as a copy pool. The volumes in this pool are processed collectively creating, by fast replication, backup versions that are managed by DFSMShsm. Recovery can be performed at the volume or copy pool level. This capability is designed to work specifically with DB2 Version 8 or later. With DFSMShsm fast replication, the backup and recovery of DB2 copy pools can be managed by DFSMShsm. DFSMShsm fast replication provides a quick, easy-to-use backup and recovery solution. This IBM Redbooks publication consists of a technical overview of the DFSMShsm fast replication function in z/os V1R12 Data Facility Storage Management Subsystem (DFSMS). It provides you with the information that you need to understand and evaluate the function, with practical implementation hints and tips. This book is written for storage professionals, database administrators, and system programmers who have experience with the components of DFSMS. It provides sufficient information for you to implement the DFSMShsm fast replication function in your storage environment. Authors This book was produced by a pair of specialists from around the world working at the International Technical Support Organization, Poughkeepsie Center. Keith Winnard is the IBM Redbooks Publications Project Leader for z/os and related topics at the International Technical Support Organization, Poughkeepsie Center. He joined IT in 1977 and worked for various clients and IBM Business Partners. He is experienced in blending traditional z/os environments and applications with web middleware and applications. Keith presents many mainframe-related topics. Jeanne Vangsness is a DFSMS Software Technical Support Engineer specializing in the DFSMShsm product area. With IBM for 26 years, Jeanne spent 19 years working with clients and developers on the DFSMS product set. She provides feedback to the DFSMShsm development in a number of areas to help improve the functionality of DFSMShsm. Jeanne co-authored several Redbooks publications, including Implementing an Open SAN, SG24-6116, and z/os 1.12 Technical Update, SG24-7895. Jeanne continues to provide assistance in other IBM Redbooks publications. Thanks to the following people for their contributions to this project: Rich Conway Bob Haimowitz IBM Development Support Team (DST), Poughkeepsie Center Ed Baker Glen Wilcock DFSMShsm development Copyright IBM Corp. 2015. All rights reserved. xiii

Judy Ruby-Brown IBM ATS Dallas Thanks to the authors of the previous editions of this book. The following individuals were the authors of the first edition, DFSMShsm Fast Replication Technical Guide, published in June 2004: Martin Berger Enete Filho Bengt Larsson The following individuals were the authors of the second edition, DFSMShsm Fast Replication Technical Guide, published in October 2011: Mary Lovelace Werner Bauer Gerhard Wesshaar Editions: The current edition (2015) has minor updates from the prior edition (2011) and does not include a Changes page. Now you can become a published author, too! Here s an opportunity to spotlight your skills, grow your career, and become a published author all at the same time! Join an ITSO residency project and help write a book in your area of expertise, while honing your experience using leading-edge technologies. Your efforts will help to increase product acceptance and customer satisfaction, as you expand your network of technical contacts and relationships. Residencies run from two to six weeks in length, and you can participate either in person or as a remote resident working from your home base. Find out more about the residency program, browse the residency index, and apply online at: ibm.com/redbooks/residencies.html xiv DFSMShsm Fast Replication Technical Guide

Comments welcome Your comments are important to us! We want our books to be as helpful as possible. Send us your comments about this book or other IBM Redbooks publications in one of the following ways: Use the online Contact us review Redbooks form found at: ibm.com/redbooks Send your comments in an email to: redbooks@us.ibm.com Mail your comments to: IBM Corporation, International Technical Support Organization Dept. HYTD Mail Station P099 2455 South Road Poughkeepsie, NY 12601-5400 Stay connected to IBM Redbooks Find us on Facebook: http://www.facebook.com/ibmredbooks Follow us on Twitter: http://twitter.com/ibmredbooks Look for us on LinkedIn: http://www.linkedin.com/groups?home=&gid=2130806 Explore new Redbooks publications, residencies, and workshops with the IBM Redbooks weekly newsletter: https://www.redbooks.ibm.com/redbooks.nsf/subscribe?openform Stay current on recent Redbooks publications with RSS Feeds: http://www.redbooks.ibm.com/rss.html Preface xv

xvi DFSMShsm Fast Replication Technical Guide

1 Chapter 1. DFSMShsm fast replication overview This chapter provides an overview of the additional features in the DFSMShsm fast replication function since Phase 1 in z/os V1.5 DFSMShsm. These enhancements allow DFSMShsm to fully use the latest FlashCopy features of the IBM System Storage DS8000 and complete the Phase 2 implementation. In this chapter, we review the concept of fast replication, FlashCopy, and the enhancements as of z/os V1.12 DFSMShsm. Copyright IBM Corp. 2015. All rights reserved. 1

1.1 DFSMShsm fast replication sample configuration We start with a sample fast replication configuration to provide a quick overview of DFSMShsm fast replication and insight into the contents of this book. 1.1.1 Fast replication diagram Figure 1-1 shows a sample FRBACKUP-based target configuration, just to provide a first look at what this book is all about. You will understand this figure and the detail behind it after you read through this Redbooks publication and are ready to create a similar configuration. General view on FRBACKUP configuration real volumes Physical volume location FlashCopy source volumes Logical volume location DS800_#1 SG1 SG2 all DS800_#2 SMS storage groups Copy Pool 1 Copy Pool 2 Copy Pools FRBACKUP FRBACKUP 1:1 mapping Logical volume location Copy Pool Backup SGs 2 Versions real volumes Physical volume location FlashCopy target volumes Might be Space efficient DS800_#1 DS800_#2 Figure 1-1 Potential fast replication target configuration The remainder of this chapter provides information about what FRBACKUP is all about and why IBM is providing this solution. DFSMShsm fast replication builds exclusively on the FlashCopy functionality in the DS8000 and any vendor disk that supports these interfaces. 1.1.2 FlashCopy function overview In a z/os and storage-management subsystem (SMS) environment, physical full volume copies are generally not useful. FlashCopy, as the DS800 implements the function, provides physical copies from a source volume to a target volume within the same DS8000 only. With DFSMShsm fast replication management, this method changed. DFSMShsm manages your configuration through enhanced SMS constructs. Figure 1-1 shows a sample fast replication configuration. It provides an overview of a FRBACKUP configuration and points out where the real physical volumes reside. It also shows the logical constructs that are wrapped around the physical volumes and storage subsystems. In this book, we focus on the DS8000 FlashCopy function. It applies in a still more restricted fashion to the ESS 800. 2 DFSMShsm Fast Replication Technical Guide

SMS already has the logical concept of storage groups to logically group volumes. Another tier of logical grouping is copy pools, which map to SMS storage groups and can have up to 256 SMS storage groups that are mapped to a copy pool. This copy pool is the source site of a fast replication configuration. The target or backup location has another SMS construct, which is a copy pool backup storage group (CPBSG). A CPBSG has all the potential FlashCopy target volumes and contains only FlashCopy target volumes. Figure 1-1 on page 2 shows a fast replication configuration as a general-purpose fast backup and fast recovery solution. DFSMShsm fast replication is geared toward DB2 but can also be used for other means when an instant backup copy of any number of application volumes through FlashCopy is required. However, Figure 1-1 on page 2 does not show the possible automatic dumps to tape from the CPBSG volumes. 1.2 Fast replication review Fast replication uses FlashCopy, which is a point-in-time copy of a volume. A point-in-time copy gives the appearance of an almost instantaneous volume copy. The process of fast data replication occurs so quickly because it builds a map, with pointers, to the source volume tracks or extents. Applications no longer a need to wait for the physical copy to complete before they can resume the access to the data. Both the source data and target data are available for read/write access almost immediately, while the copy process continues in the background. This process guarantees that the contents of the target volume are an exact duplicate of the source volume at that point in time. You can back up, recover to, and resume processing from that point in time. Most 24x7 database operations require a mirror solution that has no or little impact on application performance, and provides immediate access to a copy of the mirrored data. This access to a copy of mirrored data, which can be obtained by various techniques with a minimal impact on mirroring, is one of the main returns on investment (ROI) that many companies practice. In the past, volume-level point-in-time copies were used almost exclusively as disaster recovery backups. With new software services that are available, these copies, clones, or mirrors can be used for job restart, data mining, and application testing. 1.2.1 Point-in-time hardware support The DFSMShsm fast replication line item supports the volume-level FlashCopy function of the IBM DS8000 disk storage subsystem and any other disk storage subsystem that supports FlashCopy application programming interfaces (APIs). Tip: Appropriate microcode levels might be required to activate these features on the storage device. The process of creating a point-in-time copy has two phases. The first phase completes in a few milliseconds by constructing a map to describe the source volume. At the completion of this first phase, the data is cloned and both the source and target volumes are available for read and write access. From the user s perspective, the source and target volumes contents are an exact duplicate at this point in time, even though actual copying of data was not initiated. Chapter 1. DFSMShsm fast replication overview 3

The second phase consists of copying the physical source volume data to the target volume. The point-in-time copy is maintained and preserved by an on-demand copy of the data to the target volume. When an update request is issued for either a source or target volume data set that is not yet copied to the target volume, the write is done directly to the target and the bitmap is updated to ensure that the track from the source volume is not copied over later. The following situations are possible: Read request to the source volume The data is read from the source volume. Read request to the target volume: If the data was already copied from the source volume to the target volume, the data is read from the target volume. If the data was not yet copied to the target volume, the data is read from the source volume. Write request to the source volume If the data was already copied from the source volume to the target volume, this task results in a normal write to the source volume. However, if the data was not yet copied from the source volume to the target volume, the data is copied from the source volume to the target volume before the source volume update occurs. Write request to the target volume If the data was already copied from the source volume to the target volume, the write request results in a normal write to the target volume. However, if the data was not yet copied from the source volume, the write is done directly to the target volume and the bitmap is updated to ensure that the track from the source volume is not copied over later. 1.2.2 FlashCopy: Background copy By default, FlashCopy performs a background copy. The background copy task makes a physical copy of all tracks from the source volume to the target volume. Destaging algorithms are used to efficiently manage the background DS8000 copy process. The background copy task runs at a lower priority than normal I/O on the DS8000 in order to not affect the normal application I/O processing. The DS8000, by using the metadata structure that was created during the FlashCopy establish command, tracks which data was copied from the source to the target and manages the integrity of both copies. If an application wants to read data from the target that was not yet copied, the data is read from the source; otherwise, the read can be satisfied from the target volume. Before the DS8000 updates a not-yet-copied track on the source volume, the DS8000 performs an on-demand copy of the track to the target volume by a function that is called copy-on-write. Subsequent reads to this track on the target volume are satisfied from the target volume. After all tracks are copied to the target volume, the FlashCopy relationship automatically ends unless the persistent FlashCopy option was specified. As Figure 1-2 on page 5 illustrates, a FlashCopy relationship goes through three stages: Establishing the relationship Copying the data Terminating the relationship 4 DFSMShsm Fast Replication Technical Guide

Bitmap Source Target 1000 2000 FlashCopy empty Background copy starts... t0 FlashCopy command issued FlashCopy relationship is established. Both source and target volumes are immediately available...... although target volume is physically empty Write Read Write 1000 2000 Read and write to source and target volumes immediately possible Copy-on-write t0 1000 2000 Figure 1-2 FlashCopy with background copy t1 t When background copy is complete the relationship between source and target volume ends Volume FlashCopy is a physical copy from the very first track to the very last track, independently of the data that is on these tracks. 1.2.3 FlashCopy: No background copy When you select not to perform the background copy, the relationship is established but the background copy task of all source volume tracks is not initiated. Only the source tracks that receive application updates are copied to the target. Before the DS8000 updates a track on the source volume, the DS8000 performs an on-demand copy or copy-on-write of the track to the target volume, therefore preserving the T 0 copy. A FlashCopy relationship that was established when you selected no-background copy remains active until one of the following events occurs: An explicit FlashCopy withdraw is done to terminate the relationship. When a FlashCopy withdraw is used to terminate a no-background copy FlashCopy relationship, the target volume is left in an indeterminate state. Part of the tracks on the volume might contain data from the source volume, although other tracks might contain residual data that was on the target volume before the copy. Do not use the volume in these conditions unless it is reformatted or used for another copy operation. All source device tracks were copied on the target device because they were all updated. The FlashCopy relationship is automatically terminated, but the volume is valid. All target device tracks were updated by user applications. The FlashCopy relationship is automatically terminated, but the volume is valid. Chapter 1. DFSMShsm fast replication overview 5

When a no-background copy FlashCopy relationship is terminated, the target volume is left in an indeterminate state. Part of the tracks on the volume might contain data from the source volume, although other tracks might contain residual data that was on the target volume before the copy. Do not use the volume in these conditions unless it is reformatted or used for another copy operation. 1.2.4 FlashCopy Version 1 FlashCopy Version 1 is no longer commonly used and applies only to the ESS disk storage subsystem. The new standard for FlashCopy is V2, which is available on the DS8000. FlashCopy V1 is invoked at the volume level. The following considerations apply: The source and target volumes must have the same track format, which is also true for Version 2. The target volume must be as large as the source volume, which is also a condition for Version 2. The source and target volumes must be within the same ESS logical subsystem (LSS). This rule is not applicable any more for DS8000. A source and a target volume can be involved in one FlashCopy relationship at a time only. A DS8000 can have up to 12 target volumes that are based on a source volume. A FlashCopy establish command is issued either when invoked by a TSO command, the DFSMSdss utility, the ANTRQST macro, or by using the ESS or DS8000 Copy Services web GUI or the ESS, or when the DS8000 establishes a FlashCopy relationship between the source volume and the target volume. Restriction: When you use FlashCopy Version 1, any subsequent FRBACKUP COPYPOOL command that is issued against the same copy pool, or against another copy pool with a common storage group before all of the background copies are complete, causes the command to fail. This restriction does not exist for FlashCopy Version 2 because a source volume can be in multiple concurrent relationships. 1.2.5 FlashCopy Version 2 FlashCopy Version 2 is the standard for DS8000. FlashCopy Version 2 supports all of the FlashCopy V1 functions, plus these enhancements: FlashCopy V2 can be used for data set copies and volume copies. The source and target of a FlashCopy can be on different LSSs even within an ESS storage subsystem. Up to 12 FlashCopy relationships are allowed. Incremental copies are possible. In-band FlashCopy commands can be sent over Peer-to-Peer Remote Copy (PPRC) links to a remote site. FlashCopy consistency groups can be created. 6 DFSMShsm Fast Replication Technical Guide

In addition, the FlashCopy establish times were reduced. Figure 1-3 compares the features of FlashCopy Version 1 and FlashCopy Version 2. FlashCopy V1 Original FlashCopy V1 Updated FlashCopy V2 Lic 2.2.0 Background Copy Mode Disposition Data Movement Relationship(s) COPY or NOCOPY COPY, NOCOPY NOCOPY->COPY COPY, NOCOPY NOCOPY->COPY Ended Ended / Persistent Ended / Persistent Full Full Full or Incremental Single Single Multiple Granularity Data Set Volumes, Tracks Volumes, Tracks Volumes, Tracks, Data Set Single Single Multiple Source/Target Boundaries Same LSS Same LSS Cross LSS Cross Cluster Applies to ESS models F10, F20, and 800 Figure 1-3 FlashCopy V1 and FlashCopy V2 comparison for ESS Figure 1-3 is only relevant for the ESS disk storage subsystem. Everything that is under the FlashCopy V2 column applies to the DS8000 FlashCopy functions. Also, the capability exists to have a Metro Mirror primary volume as a FlashCopy target volume for full copy and for data set-level FlashCopy. This capability is called Remote Pair FlashCopy or Preserve Mirror (PMR) and is only available in DS8000. For more information, see Chapter 2, Planning for FRBACKUP on page 9. 1.3 DFSMShsm FRBACKUP new features There are many ways to execute FRBACKUP. Each method differs depending on your installation requirements. The new additional features that are added to DFSMShsm help increase the various ways that you can back up your data. Since z/os Data Facility Storage Management Subsystem (DFSMS) 1.5, the following FRBACKUP function was added: Use of INCREMENTAL on copy pools is provided by z/os DFSMS 1.8.0 PTF UA28767. Allowing use of an alternate CPBSG is provided by z/os DFSMS 1.9.0 PTF UA36434. Allowing PPRC primary volumes to be selected as target volumes for FRBACKUP and FRRECOV function with new keywords that are provided in PTFs: z/os DFSMS 1.8.0 UA42371 z/os DFSMS 1.9.0 UA42372 Fast replication tape support is provided in base z/os DFSMS V1.8.0. Chapter 1. DFSMShsm fast replication overview 7

The following function was added in base z/os DFSMS 1.11: Capture catalog information allows for recovery of deleted data sets that are provided in base z/os DFSMS V1.11. If an error occurs during FRBACKUP, ARC1803I lists the DFDSS failing message and VOLSER in the backup activity log to help diagnose errors. In a NOCOPY scenario, if an error occurs, a withdraw is done; now the target volume will be reinitialized after withdraw. Copy pool recovery from dump tape is provided in base z/os DFSMS 1.12.0. Fast reverse restore is provided in base z/os DFSMS 1.12.0. FlashCopy to space efficient volumes is provided in base z/os DFSMS 1.12.0. Additional items were added in z/os DFSMS 1.12.0: Up to 64 volume recovery tasks Up to 64 data set recovery tasks Up to 254 volume pairs to be backed up at one time These features are available through new parameters in the FRBACKUP and FRRECOV commands. They are described in more detail in Chapter 5, DFSMShsm fast replication commands on page 65. The remainder of this book describes the steps that are required to update your environment to implement DFSMShsm fast replication. 8 DFSMShsm Fast Replication Technical Guide

2 Chapter 2. Planning for FRBACKUP This chapter provides planning information to look into and understand before you implement FRBACKUP. It is important to understand the main intention of FRBACKUP, which we describe first and then we offer general comments about the solution. Because FRBACKUP is based on the DS8000 FlashCopy function and its variation, we categorize the different FRBACKUP configurations according to the underlying FlashCopy functions. This part includes several FlashCopy paragraphs that you can skip if you are familiar with the DS8000 FlashCopy function. This chapter includes these FlashCopy functions: Incremental FlashCopy FlashCopy with background copy FlashCopy without background copy: When the target volume is fully provisioned When the target volume is Space Efficient (SE) Remote Pair FlashCopy or Preserve Mirror (PMR) FlashCopy consistency group Various planning aspects for recovery follow at the end of this chapter. We also describe the DS8000 firmware requirements for different DS8000 models. Copyright IBM Corp. 2015. All rights reserved. 9

2.1 General FRBACKUP usage and planning considerations In z/os with system-managed I/O configurations, the full volume FlashCopy functions that are provided by the DS8000 are limited on overall usability because the DS8000 FlashCopy function is basically a full volume physical copy from a source to a target volume. FlashCopy does not distinguish among a volume label, VTOC index, or SYS1.VVDS, which is important for each volume to locate the data sets on the volume. FlashCopy physically copies a complete source volume from the very first track to the very last track to a target volume and overrides everything on the target volume. With DFSMShsm s FRBACKUP solution, this approach changed. With DFSMShsm through DFSMSdss, with system-managed storage, you can use the Copy Services functions of the DS8000, such as FlashCopy, in a productive way, which is demonstrated in the following paragraphs. Another reason to move from conventional I/O through Fibre Channel connection (FICON ) channels and through a z/os host to FlashCopy based I/O is to remove this I/O overhead from z/os and move it to the DS8000 storage subsystem. FRBACKUP uses FlashCopy and does not impose any data copy I/O overhead on the z/os host. This method includes FRRECOV, which also uses FlashCopy, and an entire pool recovery, volume-level recovery, or data set recovery does not go through FICON channels but stays within the DS8000. 2.1.1 DFSMShsm FRBACKUP system overview The FRBACKUP solution is based on the FlashCopy function of the DS8000. The software management framework is provided through DFSMShsm and DFSMShsm interfaces with the user. DFSMShsm uses DFSMSdss as an interface to the FlashCopy functions in the DS8000. DFSMShsm uses, for its DFSMSdss interface, cross-memory services to a newly created DFSMSdss address space for FRBACKUP, which is DSSFRB01, as shown in Figure 2-1 on page 11. DFSMShsm also interfaces with other system services, such as storage management subsystem (SMS) to retrieve SMS constructs and storage group volumes. DFSMShsm interfaces with the catalogs to organize and manage the FRBACKUP configuration. In particular, the Catalog Search Interface (CSI) is crucial to create a backup version successfully. 10 DFSMShsm Fast Replication Technical Guide

Figure 2-1 shows the major components that work with DFSMShsm to create a complete backup copy of an entire DB2 subsystem and all the related volumes quickly by using FlashCopy. Component interactions z/os SMS IEFPROC CATALOG IEFPROC CSI DFHSM ARC1MIGR IEFPROC DSSFRB01 ARC1CDSB IEFPROC IEFPROC DFSMSdss FRBACKUP Management DFSMSdss DFSMSdss Channel Subsystem FICON Data FlashCopy Source Target Volumes DS8000 ML1 BCDS DS8000 Logs DB2 SGs Figure 2-1 DFHSM FRBACKUP z/os component interaction 2.1.2 FRBACKUP intended use The FRBACKUP solution is geared toward DB2 installations to use FlashCopy to create complete backup versions of an entire DB2 configuration. This approach does not limit the FRBACKUP solution to DB2 only, but extra care is required when you consider FRBACKUP as a general-purpose backup solution. Figure 2-1 provides a high-level system view. It highlights a crucial interface, which is the catalog search interface (CSI) that DFSMShsm uses to retrieve the entire content of the user catalogs. The user catalog can be an Integrated Catalog Facility (ICF) user catalog or Basic Catalog Structure (BCS). DFSMShsm expects a clean user catalog, which contains only data set entries that point to data sets that reside on volumes either within the managed copy pool or outside the copy pool. CSI does not return a zero return code when the catalog in question contains orphan entries. A nonzero CSI return code prevents data set-level recovery if the data set moved or was deleted at the time of the recovery. The condition of a clean catalog is strict but necessary to create volume copies of the managed copy pool volumes successfully, which allows a successful recovery to be performed. Chapter 2. Planning for FRBACKUP 11

2.2 FlashCopy considerations that relate to FRBACKUP There are two FlashCopy types in a z/os environment: Volume-level FlashCopy Data set-level FlashCopy 2.2.1 FlashCopy target volume types With volume-level FlashCopy, we further distinguish the FlashCopy target volume type, which can be either of the following possibilities: A fully provisioned target volume that requires the same amount of disk storage space as the corresponding FlashCopy source volume. An SE volume that resides in a DS8000 extent pool-based repository where only changed data of SE target volumes is stored. FlashCopy to an SE target volume must be explicitly permitted when FlashCopy is triggered through interfaces, such as DFSMSdss. SE FlashCopy is only available for volume-level FlashCopy with no background copy (NOCOPY). It is not supported for data set-level FlashCopy. So, it is not possible to perform a data set-level FlashCopy to an SE target volume. FlashCopy source and target volumes, or data sets, are in a relationship. This relationship ends automatically when the background copy completes. In the case of NOCOPY, the relationship stays until it is explicitly withdrawn. 2.2.2 FlashCopy stages FlashCopy is performed in two stages: 1. FlashCopy logical copy completes in a few milliseconds and creates merely a bitmap structure. After the local copy competes, the target volume or data set is immediately available for reads and writes. 2. In the case of a background copy, the physical copy process copies data in tracks from the source volume to the target volume. 2.3 FlashCopy options When a FlashCopy relationship is established, you can specify how FlashCopy is to copy data from the source to the target volume: Full copy background copy After the FlashCopy logically completes, a background copy process starts and copies all data from the source volume to the target volume. If an update to a source volume track is not yet copied, this track is immediately copied copy-on-write before the update takes place on the source volume. The sequential background copy continues until all data is copied from the source to the target volume. When all data is copied, the relationship between source and target volume is terminated. To track the tracks that were already copied, the DS8000 storage subsystem maintains a bitmap for each track of the target volume. 12 DFSMShsm Fast Replication Technical Guide